COVID-19 Vaccination Personas in Yemen: Insights from Three Rounds of a Cross-Sectional Survey

We used three rounds of a repeated cross-sectional survey on COVID-19 vaccination conducted throughout the entire territory of Yemen to: (i) describe the demographic and socio-economic characteristics associated with willingness to be vaccinated; (ii) analyse the link between beliefs associated with COVID-19 vaccines and willingness to be vaccinated; and (iii) analyse the potential platforms that could be used to target vaccine hesitancy and improve vaccine coverage in Yemen. Over two-thirds of respondents were either unwilling or unsure about vaccination across the three rounds. We found that gender, age, and educational attainment were significant correlates of vaccination status. Respondents with better knowledge about the virus and with greater confidence in the capacity of the authorities (and their own) to deal with the virus were more likely to be willing to be vaccinated. Consistent with the health belief model, practising one (or more) COVID-19 preventative measures was associated with a higher willingness to get a COVID-19 vaccination. Respondents with more positive views towards COVID-19 vaccines were also more likely to be willing to be vaccinated. By contrast, respondents who believed that vaccines are associated with significant side effects were more likely to refuse vaccination. Finally, those who relied on community leaders/healthcare workers as a trusted channel for obtaining COVID-19-related information were more likely to be willing to be vaccinated. Strengthening the information about the COVID-19 vaccination (safety, effectiveness, side effects) and communicating it through community leaders/healthcare workers could help increase the COVID-19 vaccine coverage in Yemen.


Introduction
Yemen has been struck by a devastating civil war that has significantly impacted the country's overall quality of life since 2011. The war has resulted in a significant number of deaths and many injuries, with many more forced to flee their homes due to the protracted hostilities. Reports of grave children's rights violations and gender-based violence have increased [1]. In 2021, 20.7 million people (66% of the population) were estimated to be in need of humanitarian assistance. It was estimated that 16.2 million people (more than half of the population) were hungry in 2021, and over 15.4 million people (around half the population) were in need of support to access water and sanitation. Only about half (51%) of the healthcare facilities in Yemen are fully functional, and the health worker density is only 10 per 10,000 population, compared to the WHO benchmark of 22 per 10,000 [2]. About 20.1 million Yemenis (62%) are in need of health assistance. At least one child dies every ten minutes in Yemen due to preventable diseases. Furthermore, there are ongoing challenges, such as the lack of salaries for health personnel and difficulties importing medicines and other critical supplies [1].
(population at age > 17), a confidence level of 95%, and a margin of error of approximately 2.5%. The formula for calculating sample size: Sample size= (z 2 xp (1 − p)/e 2 )/1 + (z 2 xp (1 − p)/e 2 N) N-population size, e-Margin of error (percentage in decimal form), z-z-score. The three rounds of the survey followed a repeated cross-section format (rather than a longitudinal survey format); thus, the same individuals did not appear in all three rounds of the survey.
The survey was administered over the phone in the south of the country and face-toface in the northern part. In the north of the country, for the selection of the enumeration areas, governorates were identified to serve as primary sampling units (PSUs); based on this, governorates were implicitly stratified to allow for a random selection of clusters while considering the ease of access during the selection (e.g., not a conflict-affected zone, no restrictions from authorities). In turn, a simple random selection was applied for selection to be interviewed in each governorate. By contrast, the interviews in the south were carried out over the phone. More specifically, random numbers were selected from a dataset of phone numbers in the south (noting that this method impacts upon the representativeness of the sample in the south). The application of these different data collection methods did not significantly impact the response rate across the country. In other words, the number of interviews conducted are equal to the specified sample size in each round, both in the south and in the north.
The objective of the survey was to: (i) describe the demographic and socio-economic characteristics associated with a willingness to be vaccinated; (ii) analyse the link between beliefs associated with COVID-19 vaccines and willingness to be vaccinated; and (iii) analyse the potential platforms that could be used in order to target vaccine hesitancy and improve vaccine coverage in Yemen. The survey instrument included items related to (i) knowledge of symptoms, transmission, and prevention; (ii) peoples' sources of information; (iii) risk perception; (iv) information needs of respondents; (v) COVID-19-related stigma; and (vi) hesitancy or acceptance of COVID-19 vaccine. The questionnaire used for the data collection underwent a thorough review process, with input from several partners and counterparts, including the World Health Organisation as well as members of various United Nations and government coordination and decision-making bodies such as the COVID-19 task force and the risk communication and community engagement working group. Additionally, the questionnaire was pre-tested with selected participants to ensure clarity and relevance. The questionnaire is available upon request.

Statistical Analysis
We adopted a descriptive analysis of the main characteristics of three vaccination personas: (a) those willing; (b) unsure if they wanted to be vaccinated, and (c) those unwilling. In order to distil the three personas, we relied on the following question from the survey: "Would you be willing to get the COVID-19 vaccine when one becomes available in Yemen?". Furthermore, the characteristics of the three personas were grouped into three major groups: (i) socio-demographic characteristics (e.g., age, gender, occupation), practising public health and social measures (PHSM), risk perception and trust in authorities); (ii) a second group relating to attitudes and beliefs towards the COVID-19 vaccines (e.g., beliefs in the vaccine safety and side effects); (iii) the final group of characteristics corresponding to the preferred channels for reaching different personas. As outlined above, in order to understand the characteristics of the different vaccination categories, we conducted a descriptive analysis, coupled with chi2 test of the difference between categorical variables. In carrying out the analysis, we focussed on the last round of the survey (round 5) and provide the analysis of the previous two rounds in Appendix A of the paper. Table 1 provides a socio-demographic snapshot of the sample, across the three rounds. About one-third of respondents had completed secondary education and another quarter had completed some college degree, and roughly four-fifths of respondents were less than 50 years of age. Only a fraction of the sample had no or very little formal education. In round 5, about 7% of respondents could not read or write, while 15.6% had basic reading and writing skills. There were more males than females in the sample; more specifically, by the fifth round of the survey, about two-thirds of the sample consisted of males. Furthermore, the sample was almost equally split between the professions included in the study (educators, housewives, students, and office workers). Between round 3 (March, 2021) and round 5 (April, 2022), the share of respondents who believed they could become infected with COVID-19 had increased. By the fifth round of the survey data, almost half of respondents stated they felt at risk of being infected by the virus. Over time, there was an increase in confidence regarding COVID-19 information provided by the authorities, coinciding with enhanced management of COVID-19. By the fifth round, over half of respondents reported confidence or total confidence in official COVID-19 information from the authorities. However, 14.6% of respondents still had no confidence and might resist authorities' appeals for vaccine uptake. In addition, the reopening of the country, coupled with the relaxing of some of the stringent measures aimed at containing the virus, resulted in a reduction in the share of respondents practising various public health and social measures (PHSM). More specifically, by the fifth round, only about four percent of respondents practised social distancing (over the last four weeks), while about a third wore a mask in public, whereas handwashing seemed to be a more embedded habit with close to half of respondents (42.6%) still reporting washing their hands regularly with soap and warm water. Figure 1 provides a summary of vaccination intention over time. There are a few important findings that stem from this analysis. While initially, the share of respondents not willing to be vaccinated had decreased (between rounds 3 and 4), there was very little change between rounds 4 and 5. More specifically, roughly 41% of respondents stated that they were not willing to receive the COVID-19 vaccination when it became available. Second, between rounds 3 and 4, there was an increase in the share of people willing to be vaccinated; however, it had reduced between rounds 4 and 5, at the expense of respondents who were not sure/undecided. By round 5, 28.2% of respondents were willing to be vaccinated, while 30.7% reported that they were unsure. Between round 3 (March, 2021) and round 5 (April, 2022), the share of respondents who believed they could become infected with COVID-19 had increased. By the fifth round of the survey data, almost half of respondents stated they felt at risk of being infected by the virus. Over time, there was an increase in confidence regarding COVID-19 information provided by the authorities, coinciding with enhanced management of COVID-19. By the fifth round, over half of respondents reported confidence or total confidence in official COVID-19 information from the authorities. However, 14.6% of respondents still had no confidence and might resist authorities' appeals for vaccine uptake. In addition, the reopening of the country, coupled with the relaxing of some of the stringent measures aimed at containing the virus, resulted in a reduction in the share of respondents practising various public health and social measures (PHSM). More specifically, by the fifth round, only about four percent of respondents practised social distancing (over the last four weeks), while about a third wore a mask in public, whereas handwashing seemed to be a more embedded habit with close to half of respondents (42.6%) still reporting washing their hands regularly with soap and warm water. Figure 1 provides a summary of vaccination intention over time. There are a few important findings that stem from this analysis. While initially, the share of respondents not willing to be vaccinated had decreased (between rounds 3 and 4), there was very little change between rounds 4 and 5. More specifically, roughly 41% of respondents stated that they were not willing to receive the COVID-19 vaccination when it became available. Second, between rounds 3 and 4, there was an increase in the share of people willing to be vaccinated; however, it had reduced between rounds 4 and 5, at the expense of respondents who were not sure/undecided. By round 5, 28.2% of respondents were willing to be vaccinated, while 30.7% reported that they were unsure.  There are a few major findings that stem from this chart. First, as the pandemic ebbed, the authorities were less stringent regarding enforcement of various measures to stop the transmission of the virus. Indeed, as the chart shows, the share of people practising PHSM over the last four weeks is roughly half compared to the share of the respondents practising the same type of PHSM in the previous ten months. In addition, there are visible differences in the prevalence of different PHSM. Handwashing (albeit measured only in rounds 4 and 5) is the most prevalent and sustained type of PHSM. For example, in round 5, just forty percent of respondents had practised handwashing in the last four weeks. Noting that handwashing pre-dated COVID-19 and is relevant well beyond COVID-19, its endurance over other PHSM was understandable. By contrast, about one-third of respondents reported mask-wearing (face covering). The rest of the PHSM were practised by a lower share of respondents, which had drastically dropped over time. This was particularly the case with measures such as not attending the mosque and avoiding social gatherings.   There are a few major findings that stem from this chart. First, as the pandemic ebbed, the authorities were less stringent regarding enforcement of various measures to stop the transmission of the virus. Indeed, as the chart shows, the share of people practising PHSM over the last four weeks is roughly half compared to the share of the respondents practising the same type of PHSM in the previous ten months. In addition, there are visible differences in the prevalence of different PHSM. Handwashing (albeit measured only in rounds 4 and 5) is the most prevalent and sustained type of PHSM. For example, in round 5, just forty percent of respondents had practised handwashing in the last four weeks. Noting that handwashing pre-dated COVID-19 and is relevant well beyond COVID-19, its endurance over other PHSM was understandable. By contrast, about one-third of respondents reported mask-wearing (face covering). The rest of the PHSM were practised by a lower share of respondents, which had drastically dropped over time. This was particularly the case with measures such as not attending the mosque and avoiding social gatherings.

Persona 1: Willing to Be Vaccinated
There is some scant evidence that those willing to get vaccinated were slightly younger (Table 2), although the relationship between age and willingness to vaccinate is statistically insignificant. Furthermore, about a third of those with college degrees and close to half of respondents with higher degrees tended to be willing to be vaccinated. Consistent with the established notion from other countries and studies of other health practices, men were more likely than women to be willing to receive a COVID-19 vaccination. About a third of those who felt at risk of becoming infected with the virus were willing to receive at least one dose of the vaccine. Table 2 also provides some evidence that this vaccination persona tended also to adhere to public health and social measures (PHSM). For example, more than a third of those who practised social distancing were willing to receive the COVID-19 vaccine. Similarly high was the share of these respondents who stayed away from the mosque and were willing to receive a vaccination.  Table 3 summarises the analysis of vaccination status and knowledge regarding COVID-19. There are a few conclusions that stem from the table. First, the willingness to be vaccinated increased as knowledge about protecting oneself from the virus increased. More specifically, 40.6% of those with excellent knowledge about how to protect themselves were willing to be vaccinated. Similarly, willingness to be vaccinated increased as trust in the official information from authorities and their ability to deal with the virus increased. In addition, willingness to be vaccinated is a function of risk perception of the dangers of the virus. For example, 40.3% of respondents who thought the virus was dangerous were willing to be vaccinated. We next turned to the link between vaccination status and beliefs about COVID-19 vaccines (Table 4). Consistent with the existing research, positive beliefs about the vaccine are associated with a higher willingness to be vaccinated. Nearly half (48.2%) of respondents who thought that the vaccine is effective were willing to be vaccinated. Similar findings emerged when considering beliefs about side effects. The results from the previous two rounds are reported in Appendix A, Table A3, and they were consistent with the findings emerging from round 5. Various sources of information could be used as a vehicle to increase vaccine acceptance and, thus, vaccine uptake. This, however, depends on what type of information source is most trusted vis-à-vis COVID-19 vaccines. Against this background, we next turned to the link between vaccination status and the most trusted source of information (Table 5). Half (50%) of respondents listing community leaders as the most trusted COVID-19 information source were willing to be vaccinated (Table 5). Similar findings emerged from the previous two rounds (Appendix A, Table A4). In addition, in some of the previous rounds (e.g., round 3) we also found evidence that those who listed community healthcare workers as a trusted source of information were more likely to be willing to receive a COVID-19 vaccination. This persona tends to trust communication materials and community leaders more than other personas trust these sources of information. As in the case above, here as well, age, gender, and education were the main correlates of this persona (not vaccinated and undecided). A large share of the unemployed (38%) were undecided regarding a possible vaccination, suggesting a link to employer encouragement being a strong incentive for vaccination. About a third of those with no opinion regarding potential infection with the virus were undecided regarding obtaining a vaccine. Furthermore, no discernible link emerged between practising PHSM and being undecided about potentially obtaining a COVID-19 vaccination. About a quarter of those who believed that the vaccine is effective were undecided regarding taking it (slightly lower compared to those who did not think that there were serious side effects if/when taking the vaccine). This persona appeared to draw information from a wide range of sources, which may be contradictory.

Persona 3: Not Willing to Get Vaccinated
As with the persona above, here as well, we found some evidence that this vaccination persona was older than the other categories. In addition, less educated by a significant margin. About two-thirds of respondents who could not read and write were not willing to get vaccinated. About half of women were unwilling to obtain a COVID-19 vaccine (about 15 percentage points higher than men). Almost two-thirds (63.5%) of respondents who stated that they did not believe they were likely to get infected with the virus were also unwilling to be vaccinated. Table 2 also provides the results of the link between vaccination status and practising different PHSM (wearing a mask in public, washing hands, keeping physical distance, and staying away from crowds/the mosque). The question on the PHSM practice was asked in reference to two time periods: 10 months ago and four weeks ago. The results of this analysis were unequivocal: those who did not practice PHSM were also less likely to be willing to be vaccinated. For example, 48.3% of respondents who claimed they did not wear a mask in public were unwilling to be vaccinated.
This vaccination persona was less knowledgeable about the COVID-19 virus (Table 3). For example, 81.4% of those with no knowledge were unwilling to obtain the vaccine. By the same token, this persona tended to believe that the virus is not dangerous. More specifically, 72.5% of those claiming the virus is not dangerous were unwilling to be vaccinated. Furthermore, this vaccination persona held negative attitudes and beliefs towards the vaccines. For example, about half (52%) of respondents who did not think that the vaccine is effective were unwilling to be vaccinated (Table 4). Finally, this group of people tended to trust their family and friends more than other personas for information regarding COVID-19.
As a complementary analysis, we also conducted the standard logit modelling analysis, where the three vaccination personas appeared as dependent variables in three separate models. The explanatory variables were grouped into three major groups: (i) sociodemographic variables (e.g., age, gender); (ii) practising some of the most common public health and social measures (e.g., wearing a mask, washing hands); and (iii) beliefs about the COVID-19 vaccines (e.g., effectiveness, side effects). The results are reported as Appendix A tables (Tables A4-A6). The analysis supports the findings from the descriptive statistics; more specifically, certain demographic variables (e.g., gender) and variables capturing beliefs about COVID-19 vaccines explained the decision to obtain a COVID-19 vaccination.
In order to capture the PHSM/vaccination status nexus over time, we pooled the three waves together and used the three vaccination personas as dependent variables in three separate bivariate logit models (where the variables capturing different PHSM were used as independent variables). We repeated the analysis twice, first using PHSM practised over the last ten months and then over the last four weeks. The models also controlled for the survey wave (i.e., taking into account any temporal changes occurring over the three different waves). The findings (reported in Appendix A, Tables A7 and A8) were unequivocal: those more willing to be vaccinated were also more willing to adhere to various PHSM (both over the last ten months as well as over the last four weeks).

Discussion
To the best of our knowledge, this is the first comprehensive attempt to describe various vaccination personas in Yemen, relying on a sample covering the entire country and spanning three points in time. In that respect, there are a few interesting findings that emerge from this study. First, our findings on the socio-demographic characteristics of vaccination willingness are consistent with the existing evidence. A recent paper using two waves of repeated cross-sectional surveys from the Middle East, North Africa, and Eastern Mediterranean region [11], for example, found that men, on average, were more likely to be vaccinated and to be willing to be vaccinated once vaccines were available to them. The same study also posits that men may be also advantaged by their higher level of mobility than women in parts of the region, and their higher engagement in formal employment, which may offer additional incentives for vaccination. The same study showed that women were disproportionately affected by misinformation about fertility, which also seemed to affect their willingness to be vaccinated. In addition, it has been argued that women are more likely to embrace conspiracy theories about the virus [12]. Other potential factors that can contribute to higher rates of vaccine hesitancy among females include the higher levels of fear of injections or side effects and the observation that the disease is more deadly in males [12]. Furthermore, in countries where men have greater access to healthcare services and the means to pay for vaccination than women, men may be more interested in the COVID-19 vaccination [13,14].
A study by Bitar et al. [7], also found that men were more likely to be willing to be vaccinated, while women were more likely to reject the vaccine. That study also finds that those with lower income are likely to reject the vaccines. While in our study, we did not have a variable capturing income, our variable on education attainment could be considered as a proxy for socio-economic status.
We also found that respondents who were practising some forms of preventative measures (e.g., wearing a mask, washing hands, practising social distancing) were more likely to be willing to obtain a vaccination. This finding supports the general health motivation construct in the health belief model [15], and aligns with social identity theory [16], which suggests that people who practise one health behaviour (such as vaccination) are more likely to practise others, such as PHSM in relation to the containment of COVID-19. Some of these associations were explored in a recent paper involving two rounds of repeated cross-sectional data on 14,000 respondents from the wider MENA region [11].
One of our principal findings relates to the link between vaccine beliefs and willingness to be vaccinated. To date, a large body of evidence stemming from the Middle East, North Africa, and Eastern Mediterranean region has also documented the link between vaccine beliefs and vaccination status. A study about vaccination among healthcare workers in Egypt, for example, found that the reasons for vaccine acceptance revolved around safety and effectiveness, while fear of side effects was the main reason for vaccine hesitancy [17]. Concerns about safety as well as a general lack of trust in the vaccines, were the main reason for vaccine hesitancy among healthcare workers in Sudan and Iraq [18,19]. Lack of trust in vaccine effectiveness and fear of side effects were the also main reasons for refusing to be vaccinated among the general population [17,[20][21][22], while the belief in the effectiveness and benefits associated with the COVID-19 vaccination were the main reasons for vaccine acceptance [20,23].
These findings need to be interpreted within the broader context of the political situation in Yemen, which affected the availability of accurate information and vaccination services (including the availability of vaccines), particularly in the northern DFA (de facto authority)-controlled provinces. Across Yemen, a variety of misinformation about COVID-19 immunisation has taken root. The most frequently stated reasons for poor vaccination uptake by key informants in a study by Bin Ghouth and Al-Kaldy [9] were comparable to the findings of a sub-national survey carried out in early 2021 [24]. Some participants in that study saw the vaccination as a planned "scheme" that posed a danger to their health. Some individuals felt that the vaccination would cause death over time rather than instantly. Some claimed that the vaccine effort is a plot to create Muslim infertility [25]. Others said that the West was supplying Yemen with inadequate vaccinations [26]. People in the northern regions, on the other hand, did not see COVID-19 as a danger [24].
Finally, we found that respondents using certain sources of information (e.g., community leaders and volunteers) were more likely to be willing to be vaccinated. Compared to the regional average, trust in health workers is lower in Yemen, which can reasonably be expected to have an impact on vaccine uptake; the research in the area of vaccine demand generation has distilled two approaches. The first, more passive one, has relied on the use of mass media (TV and radio) and printed materials (banners, leaflets, posters) [27]. The second approach involved deeper face-to-face engagement with households and individual caregivers-often by trained volunteers from the community using interpersonal communication and behaviour change approaches. The success of this approach relies on extensive efforts by the community outreach workers to directly interact with the community as well as with individual caregivers. Even though the second approach is more labour intensive (and more expensive), it may also yield higher returns per contact when it comes to vaccination uptake, especially given the lower trust in health workers in Yemen.
There are some limitations associated with this research. First, the analysis is descriptive and only explores the correlation between vaccination status and the variables of interest. Correlations may be confounded by other observed and unobserved variables. In that respect, we cannot infer any direct causal links by using this methodological approach. Second, some questions changed over the course of the five rounds (e.g., additional categories were added to the most trusted source of information question), which may have some implications on the overall responses collected through this question. As the estimation and projection of demographic data in Yemen is of poor quality, the survey did not develop survey weights. More specifically, the results were not weighted for survey weights to address the representativeness of the sample. These limitations notwithstanding, there are some broad conclusions that stem from this research. First, we found that gender and socio-demographic status (e.g., education attainment) were significant correlates of vaccination status, consistent with existing knowledge. Second, respondents with better knowledge about the virus and with better confidence in authorities' (and their own) capacity to deal with the virus were more likely to be willing to be vaccinated. Consistent with the health belief model, practising one (or more) preventative measures in relation to COVID-19 was associated with a higher willingness to get a COVID-19 vaccination. In addition, beliefs around the COVID-19 vaccines were also linked to willingness (or lack of willingness) to obtain a vaccination. Finally, those who relied on community leaders/healthcare workers as trusted sources of COVID-19-related information were more willing to be vaccinated.
Finally, there are some broad policy recommendations that stem from this research effort. Any focus on individual motivation for vaccination relies on the basic requirement that adequate vaccination services are made available to all communities. That said, outreach to communities and a localised focus on the needs of those who are undecided about vaccination can be effective in increasing uptake, thereby also increasing the social norm around being vaccinated. Supplying them with information about the COVID-19 vaccines (e.g., safety, effectiveness, and side effects) and access to trusted and skilled health workers could mitigate fears and increase confidence in the vaccines. Identifying vaccination champions among families/communities could further allay some of the fears associated with vaccines (e.g., fears of side effects). Religious leaders and other community leaders (including females) can have a strong influence on communities in Yemen, both positively and negatively-and should be considered key partners, especially in terms of understanding and addressing the needs of local communities. Funding: UNICEF has received grants from GAVI, via the ACT-A funding stream under the COVID-19 global response to support risk communication and community engagement for vaccination uptake, part of which supports the interventions reported herein.

Institutional Review Board Statement:
This study was conducted by UNICEF for the purpose of guiding and informing Risk Communication and Community Engagement Interventions conducted by humanitarian agencies in Yemen and not as part of a formal process for academic research. The humanitarian agencies involved in designing the study including WHO as well as members of various coordination and decision-making bodies such as the COVID-19 task force and the Risk Communication Community Engagement working group concluded that the study poses no risk to participants given the aspects the study is researching and that no personal identifiable information about participants will be collected.

Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.
Data Availability Statement: Data available upon request.

Conflicts of Interest:
The authors declare no conflict of interest.